Pagina's

zaterdag 13 september 2008

Traffic Watch

Flying the Grumman has become safer once again, with the installation of the Traffic Watch ATD-300. This little box warns the pilot about conflicting traffic in the area. It’s like the smaller brother of TCAS (Traffic Alert and Collision Avoidance System), software that all the commercial airliners have under their wings.

Traffic Watch uses the signals of a transponder, a machine that transmits information about callsign, altitude, position and speed of an aircraft. Have you ever seen traffic controllers stare at a radar screen full of moving dots and figures? Well, these dots are in fact the signals of transponders. Traffic Watch scans the airspace around your plane and ‘reads’ the signals of other transponders in a range of 5 Nm. A display informs the pilot about altitude and distance to the other aircraft (in this example 5 NM and 700 FT).

In the Grumman, this wonderful piece of machinery is connected with the headset as well. That way traffic is announced by a female voice firmly stating ‘Traffic Nearby’ in your ear. Must say she took me by surprise the few first times…

I flew with the system recently and I must say it seems to work pretty good. Funny how you even get a warning about the pilot in front of you while taxiing on the ground. And while I was waiting my turn to take off, Traffic Watch picked up the signal of the aircraft on final (1 NM / 300 FT). Enroute, I got about 3 messages, two of witch I saw with my own eyes.

Is this useful? I think it is! In controlled airspace you’ll have somebody on the ground taking care of you, although off course you still have to look out the window. Traffic Watch can be like a safety backup. The system really gets useful when flying in uncontrolled airspace where a VFR pilot can use any extra pair of eyes. But be aware an airman always remains responsible for his of her own separation. The major downside of Traffic Watch is off course that it only works because of the transponder of other aircraft. We all know there are a lot of airplanes that don’t have a transponder on board. Or maybe there is a transponder but it’s not turned on, or broken, or it is transmitting wrong information. In all these cases, it is impossible for Traffic Watch to ‘see’ the other pilot heading straight for your aircraft. Relying fully on the ATD-300 at that time can ruin your whole day. Always keep in mind this: a VFR pilot has to look outside and scan for other traffic continuously. That nice lady in the right seat, called Traffic Watch, is only a conformation of what you are seeing outside for yourself.